1997 SLTX discontinued Parts - fuel tank vacuum/pressure check valves?

[Freeflyer38]

Hey all, just joined, first post.

Ski out to the lake first time this year, encountered really bad sputtering problems after warm-up.

Input from other owners was fuel system check valves. Attempted to find on multiple sites and they were all marked discontinued!

Any help or guidance greatly appreciated.

[K447]

Welcome.

This link has lots of useful info

http://polarispwcknowledge.shorturl.com/first-things-to-do

Is this machine new to you?

Are you referring to check valves inside the carburetor?

[Freeflyer38]

No, about 10 years. Always been very reliable and ran great last season. Was advised of two small check valves in fuel lines. I looked up part numbers from schematic and can’t find supplier. Wondering if alternatives are available? Seem to be a very common part for Many other models when searching the part number.

[K447]

What is the part number?

[Freeflyer38]

7052118 and 7051015

[K447]

7052118 and 7051015

Ah, the vacuum relief (7052118 ) and pressure release (7051015) check valves for the fuel tank venting.

http://www.adeptpowersports.com/oem-parts/1995-polaris-slt-750-b954170-fuel-system-slt-750-b954170-assembly.html?partnum=7052118

Are you experiencing excessive air pressure build-up or vacuum within the fuel tank?

In normal operation the fuel tank will never have suction as the vacuum relief valve will flow air into the fuel tank.

Positive air pressure rise inside the capped fuel tank is normal but limited to about 1.5PSI by the release valve.

Symptoms of fuel tank venting problems tend to occur after riding the machine for a while and consuming fuel from the tank. Leave it sitting long enough after the problem occurs (so the tank air pressure slowly equalizes) and the engine problem goes away until ridden again.

The easy check for this is to crack the gas cap open just enough to allow air flow, then see if the engine now runs normally even with riding duration.

Or ride it until the problem appears, crack open the gas cap, note any pressure release, then see if the engine problem immediately goes away.

If either of these venting check valves has been removed/replaced, check that the valve is not installed backwards or in the wrong location.

[Freeflyer38]

You nailed it, exactly what was happening. End of the day I figured out (after a methodical process of elimination of fuel delivery system) that simply relieving the gas tank cap pressure/vacuum seem to illuminate the problem. Now I’m in search of the replacement valves, just as with your attached link, I am finding them “not available“? Being such a commonly spec. item surely there must be a supply and or OEM compatible replacement available, I would think.

[K447]

Which check valve is stuck closed, vacuum or pressure?

You might try removing it and cleaning the valve with some medium grade solvent.

Also inspect for possible vent blockage from a spider nest or mud dobber inside.

Others on here might have good used parts to offer.

I have not looked for alternative source/brand replacements for these Polaris fuel tank check valves. Others on here might have that info at hand.

[Freeflyer38]

Not sure which one yet, I will spend some time investigating more this weekend because they don’t seem very easy to find. Thank you and I will follow up with a post.

[xlint89]

When removing the gas cap, does it hiss? (sucking air) Or does it pop the cap off? (too much pressure)

My guess is vacuum. Too much pressure would result in flooded carbs.

It's pretty easy to test both of them.

Remove the small one from the fuel tank vent line. The black and white one. Put the fitting in your mouth and suck. It should easily pass air one way and not the other.

Remove the pressure relief valve usually inserted into the rubber vent. Do the same test for that.

Remove the fuel cap and blow through the vent hose to make sure it's not clogged.

Now re-install the vents in the correct position. Black and white allows air IN to the fuel tank. The pressure relief valve attached to the rubber vent allows air OUT after built up pressure is reached.

[Bman4455576]

I replaced them with 2psi 1/4 6mm plastic fuel ones.

I figured carbs max psi is 8 so anything below should be fine .

My oem ones started to funtion with spit.

Some silicon spray or rubber lubricant after a clean with solvent might save them.